INTERPERSONAL SENSITIVITY PREDICTS DEPRESSIVE SYMPTOM RESPONSE TO THECIRCADIAN-RHYTHM DISRUPTION OF NIGHTWORK

This paper reports the results of a study designed to explore the vali dity of a shiftwork model of affective disorders. Fifty-five student n urses doing nightwork for the first time were recruited to a study des igned both to replicate an earlier study of the effects of nightwork o n cognitive, emotional and neurovegetative measures and to assess the effects of nightwork on personality measures and the role of personali ty factors and nightwork induced disturbances in predicting accommodat ion to nightwork. As in the earlier study, concentration, interest, en ergy, sleep and appetite were significantly disturbed by nightwork and there was an increased perception of recent criticism from others. Th e findings from both studies were, therefore, aggregated to explore fu rther possible relations between outcomes and the pre-nightwork level of affective symptoms and sensitivity to interpersonal criticism. Thes e predicted poor response. In contrast, measures of cognitive style an d symptom interpretation did not predict outcome. The findings are not inconsistent with proposals that disturbance of circadian rhythms con sequent on psychosocial disruptions may play a part in the genesis of or maintenance of depression. They also support a proposal that nightw ork induced changes may be a suitable human model for investigation of aspects of the affective disorders.